Cryptic Diversity in Resulting from Sequence-Based Species Delimitation Analyses.

is an extremely widespread fungus involved in associations ranging from mutualistic to pathogenic and is the most frequently represented species in sequence databases, such as Genbank. The taxonomy of species, currently based on the integration of molecular data with morphological and cultural characters, is in frequent need of revision. Hence, the recently developed species delimitation methods can be helpful to explore cryptic diversity in this genus. Considering a previous study that reported several hypothetical species within , we tested four methods of species delimitation using the combined DNA barcodes internal transcribed spacers, translation elongation factor 1-α and actin 1. The analyses involved 105 isolates, revealing that currently available sequences of in GenBank actually represent more than one species. Moreover, we found that eight isolates from this set should be ascribed to . Our results revealed a certain degree of discordance among species delimitation methods, which can be efficiently treated using conservative approaches in order to minimize the risk of considering false positives.